Dog respiratory illness cases confirmed in Nevada, Pennsylvania. See map of impacted states.

Two new states have officially recorded cases of Atypical Canine Infectious Respiratory Disease Complex (aCIRDC) this week, bringing the total number of states with sick dogs up to 16.

Nevada and Pennsylvania were added to the 14 states that the Louisiana State University School of Veterinary Medicine listed as seeing the disease.

The American Veterinary Medical Association recorded Pennsylvania as having the disease, USA Today previously reported. The Las Vegas Sun reported that a veterinarian in Henderson, Nevada had reported seeing cases and a school spokesperson confirmed that the reports were used to add the state to the list.

The exact cause of the disease is still unknown, though researchers in New Hampshire suggest that "a funky bacterium" could be responsible.

A paw's memory:Her dog died from a respiratory illness. Now she’s trying to help others.

Map shows confirmed cases of dog respiratory illness

Dog respiratory illness symptoms include coughing, lethargy, nasal discharge

Experts encourage dog owners to contact their veterinarians immediately if any of the symptoms occur, especially those that can lead to pneumonia.

• Coughing and sneezing
• Difficulty breathing
• Rapid breathing
• Wheezing or nasal whistling
• Dehydration
• Difficulty exercising
• Fever
• Nasal or eye discharge
• Loss of appetite
• Weight loss
• Lethargy